Former EastEnders actress Gemma McCluskie was beaten to death by her brother after a row over an overflowing sink, a court heard today.
Tony McCluskie had left taps on at the flat they shared and Miss McCluskie, 29, thought this was the "last straw".
She drove home to ask the cannabis-smoking McCluskie to leave but was never seen alive again, the Old Bailey was told.
Crispin Aylett, QC, prosecuting, said McCluskie killed his sister, cut up her body and dumped it in the Regent's Canal in east London.
He then led police on a "wild goose chase" after reporting her missing in March, last year, jurors heard.
McCluskie, 35, of Pelter Street, Shoreditch, east London, has pleaded guilty to the manslaughter of his sister but denies murder.
He claims to have "blanked out" after arguing with her and has no recollection of killing her, the court was told.
Miss McCluskie played Kerry Skinner, the niece of Ethel Skinner, in the BBC soap in 2001.
Mr Aylett said: "For some time, there had been tension between Miss McCluskie and her brother.
"To Gemma, this was largely as a result of the defendant's habitual use of cannabis - and its most toxic form, skunk.
"Gemma told a friend 'He's permanently stoned. He puts a spliff in his mouth first thing in the morning and doesn't know what he's doing'.
"On Thursday March 1, last year, McCluskie had got up, gone to the bathroom and forgotten the taps were on in the sink.
"Unsurprisingly, Miss McCluskie was exasperated by this. She had had enough.
"Later, while she was out, her friends heard her arguing on the telephone with her brother about what had happened.
"It is clear that Gemma regarded this incident as the last straw and that she wanted the defendant to move out."
Mr Aylett said the next day, McCluskie sent his sister a text pretending she was still alive and ending "Love ya xx".
Her friends had grown anxious about her and had not been able to contact her.
"A number of them began calling or sending texts to the defendant asking if he had heard from her," Mr Aylett added.
To one on Saturday night, he replied: "She didn't take the car, keys are on the side in the kitchen plus we wouldn't know if she took any clothes (as) she (has) so many!"
Then he reported her missing to police who from details given to them by McCluskie, categorised her disappearance as low risk.
On Sunday, McCluskie told officers that a former boyfriend owed her money and police should speak to him.
One hundred friends held a meeting in a local pub and then went out distributing leaflets appealing for information.
McCluskie did not turn up at the pub until after the meeting had broken up, said Mr Aylett.
On Tuesday morning, a woman navigating her barge on the canal in Hackney, noticed a suitcase floating in the water. It hit the side of the vessel and sprung open.
He said: "Inside was a female torso, no legs, no arms and no head."
Miss McCluskie had been identified by a small tattoo of a bow on her body.
Over the next fortnight, her arms and legs were recovered separately from the water.
But her head, which had been dumped in the canal at the same time, was not found until September.
Mr Aylett said McCluskie told police that his sister had been seen in a local kebab shop after she went missing, and that she had visited their mother in hospital.
But scientists had found blood in the bathroom and a blood-stained knife in the kitchen of the flat.
Police discovered that a man with a heavy suitcase matching McCluskie's description had taken a minicab to the canal the day after his sister disappeared.
Blood was found in the boot of the car and McCluskie's father and brother "no doubt with heavy hearts" said they recognised him from CCTV.
Mr Aylett continued: "The defendant must have killed Gemma, no doubt in the course of a quarrel.
"He then dismembered her body before disposing of the body parts, including the head, in the canal.
"The defendant had seemed keen to help the police with their investigation.
"In fact, the defendant was leading the police on a wild goose chase."
A pathologist had found bruises on Miss McCluskie's arms and legs made before she died.
He had also found cuts to her scalp indicating that she had been struck over the head at least twice with a blunt instrument.
Mr Aylett added: "The defendant claims not to know how he killed his sister.
"He describes having had an argument with Gemma. After that, it is said that everything is a blank.
"He does not remember killing her, nor can he recall cutting her up, nor does he remember dumping her body in the canal."
But this was not accepted by the prosecution.
"No doubt he did it in the heat of the moment, no doubt he soon came to regret what he had done," added Mr Aylett.
"He did everything he could to put himself beyond suspicion."
A forensic anatomy expert believed a cleaver was most likely to have been used to carry out the dismemberment of Miss McCluskie's body over a period of two to three hours, Mr Aylett said.
The court heard McCluskie received a series of hoax telephone calls following his sister's disappearance.
In the first call, the defendant was told that if he wanted to see his sister again he must take £2 million to Benfleet International Station.
A second call was made requesting that he also bring $500 worth of Iraqi currency, before a third hoax call repeated the demand for £2 million.
When the defendant asked to speak to his sister, the caller said Miss McCluskie had been stripped of her clothes and was being kept in a locked room, Mr Aylett said.
"The truth, it may seem to you, is that the defendant could not have believed his luck," Mr Aylett said.
"While there is no reason to suppose that the defendant had put the hoaxer up to making these calls, the calls can only have added to the state of confusion as to Gemma's whereabouts."
Police later traced the telephone calls to an address in Kent and arrested a man on March 8.
The trial was adjourned until 10.30am tomorrow.