Police are to speak to "key individuals" over allegations that Cabinet minister Chris Huhne tried to evade punishment for speeding.
Essex Police said contacts would be made as part of efforts to establish whether any offence had been committed.
Detective Superintendent Tim Wills said: "There are many lines of inquiry to be taken and the team are still working to establish if an offence has been committed.
"Obviously this will entail speaking to key individuals identified by the inquiry team. It would not be appropriate to release any more information prior to progressing these lines of inquiry."
The news will heap more pressure on Mr Huhne over claims that he asked his then-wife Vicky Pryce to accept penalty points on his behalf in 2003.
There have been reports that economist Mrs Pryce - whom the Liberal Democrat Energy Secretary left last year for another woman - is prepared to confirm the allegations to detectives.
Tory Justice Secretary Ken Clarke warned today that his Liberal Democrat colleague was "in trouble" over the controversy.
Mr Clarke told BBC Radio 5 Live he had no reason "at the moment" to doubt Mr Huhne's denials, but he said he hoped the situation would be resolved one way or another as quickly as possible.
"I have no idea whether there is anything to prove him wrong," Mr Clarke said.
"I realise he's in trouble and I hope somebody sorts out whether it be true or not. But I've known him for years, long before he was a colleague, and he insists it is untrue, and at the moment I have no reason to disbelieve that."
He went on: "The Cabinet has not discussed it. He does not need the full backing of the Cabinet unless and until anyone can undermine him."
Earlier, Downing Street indicated that David Cameron still had confidence in Mr Huhne.
"The position on Chris Huhne has not changed," the Prime Minister's spokesman said. "He denies all the allegations on the issue."