The partner of Mick Jagger’s granddaughter has been missing for days in the U.K., prompting the famous family to ask for the public’s help.

Late last week, Alexander Key was reported missing in Boscastle, a village on the coast of Cornwall, the Devon and Cornwall Police said in a statement. The 37-year-old chef shares two children with Assisi Jackson, the granddaughter of the Rolling Stones frontman, the BBC, Hello! magazine and CornwallLive reported.

While it was believed that Key was last seen on Friday, Jan. 23, at 2:20 p.m. local time at a pub, new footage reveals further details about his movements, officials said. CCTV images showed the chef on Saturday, Jan. 24, at 3:25 p.m., as he walked by The Wellington, a pub located on Old Road, in the direction of Boscastle Harbour, near the River Valency, police said.

In the new images of Key, he’s wearing a blue waterproof jacket over a red shirt and black sneakers. He is 5 feet, 8 inches tall, with a medium build and bright blonde hair. Key is known to wear bright colors, authorities said.

In their initial statement, police said they were “growing increasingly concerned for the welfare” of Key.

The Devon and Cornwall Police and representatives for the Rolling Stones did not immediately respond to PEOPLE’s requests for comment.

In a plea for help, Jackson’s mom, Jade Jagger, posted information about Key’s disappearance on Instagram on Monday, Jan. 26. In response, some followers asked for more details to help in the search, while others offered their support.

Another person wrote, “Thinking of Assisi, Alexander and their daughters. I hope Alexander turns up safe.”

Key and Jackson have been together since 2010, Hello! magazine reported. They welcomed their first daughter in 2014.

When Jackson’s rockstar grandfather learned of her first pregnancy, he was quick to congratulate her.

“He said, ‘Well done,’ and I said, ‘I didn’t have to try too hard,’ ” Jackson told the magazine ahead of the birth of her first child. (The rocker is the father of eight children.)

In 2019, the couple revealed that they were expecting their second child together, another girl.

“I’m so happy to share the amazing news that Alex and I are having our second daughter this spring,” Jackson told Hello! magazine in March 2019. “We cannot wait to meet her!”

Anyone with information about Key’s whereabouts is asked to call the Devon and Cornwall Police.