Police boarded a plane at Heathrow airport today and arrested a man.
The arrest was made just hours after detectives named a suspect they want to trace in connection with the shooting of policewoman Rachael Bown in Nottingham.
It was unclear whether the arrested man was Trevon Kyron Thomas, 24, from the Bilborough area of Nottingham, who is wanted over the shooting.
The plane was stationary when officers boarded it at 11am.
The Metropolitan Police and Nottinghamshire Police refused to immediately confirm whether the arrest was linked to the Pc Bown inquiry.
Miss Bown, a 23-year-old probationary officer, was blasted in the stomach shortly before midnight on Monday while investigating a burglary in the Lenton area of Nottingham.
Detective Chief Inspector Dave Giles said: "I'm appealing for any information which could help us trace this man as a matter of urgency.
"If you see this man or know where he is now, you should not approach him but dial 999 immediately."
Nottinghamshire Police have also issued a photograph of Thomas.
He is described as a dark-skinned black male, 5ft 9in and of slim build. He is thought to have short, cropped black hair.
He has slight facial growth and brown eyes, the force said. He has piercings in both ears in which he sometimes wears ear studs, and he has one or more gold teeth.
Thomas was born in Trinidad and speaks with a mild Caribbean accent.
This morning, Miss Bown was awake in her bed at the Queen's Medical Centre in Nottingham, where she is in a stable condition after undergoing a second emergency operation yesterday.
She had the operation after a "setback" in her condition. She had undergone five hours of emergency surgery on Tuesday.
The shooting happened when she and an experienced male colleague followed up a report of a burglary and spotted a suspect.
She was hit in the lower abdomen, below the level of her body armour, just seconds after leaping out of the passenger seat of her patrol car.
Police have so far said it was unclear whether the gunman was in any way connected with the burglary at the house in Lenton Boulevard.
Miss Bown was nearing the end of a two-year probationary period with Nottinghamshire Police and had only recently transferred to the city centre beat.
Her family has kept a vigil at her bedside since she was injured.
The Divisional Commander for Nottingham city centre, Chief Superintendent Marcus Beale, said: "We have been delighted with the support we have had from the public. Their words of support for Rachael and her colleagues have come from across the country.
"We now ask people to help again and help us locate Trevon Thomas. We are keen to trace him in connection with this investigation and to speak to him about various matters.
"People do know who he is and we would urge those people to contact us immediately."Reuse content