Police have arrested a second man on suspicion of murdering missing schoolgirl Alice Gross.
The 51-year-old man was arrested by officers in Hanwell, west London this afternoon.
It follows the arrest yesterday of a 25-year-old man on suspicion of the teenager's murder, who police have been given more time to question.
Both men remain in custody at a west London police station, Scotland Yard said.
The Metropolitan Police said the two arrests are "independent" of each other.
A Met spokesman said: "All lines of inquiry are still open and this remains a missing person investigation at this stage."
Alice, who suffers from anorexia, went missing 12 days ago after she left her home in Hanwell in the afternoon, but failed to return.
She was last seen by her family at 1pm on August 28, and was captured on CCTV at 4.23pm that day walking along the Grand Union Canal near her home.
Specialist police divers in black wetsuits and breathing apparatus have been combing the west London waterway where she was last spotted.
Sniffer dog handlers with a golden Labrador have taken to the canal on a red dinghy boat to scan it for evidence.
Police have trawled through hundreds of hours of CCTV footage and carried out "extensive" searches using specialist officers in the hunt for the missing schoolgirl.
Alice is white, 5ft 2ins tall, of very slim build and with shoulder-length, light brown hair.
She was last seen wearing dark blue jeans and a dark green lacy cardigan and carrying a dark rucksack, which was recovered last week. She may have been wearing denim blue Vans shoes and tartan-framed spectacles.
Police said they were "especially concerned" as Alice has not been well recently.
Officers are also urging anyone who may have befriended Alice while on a song-writing workshop at the Camden Roundhouse to come forward.