Millwall chief executive Steve Kavanagh has paid tribute to the “extraordinary and exemplary” contribution of late owner and chairman John Berylson, who has died aged 70.

The club announced on Tuesday evening that Berylson had “lost his life in a tragic accident”, but gave no further official details.

It has been reported the American businessman was involved in a fatal car accident while driving alone in the United States.

The Falmouth Police Department in Massachusetts issued a statement on Facebook on Tuesday concerning a single vehicle crash on Cape Cod, subsequently said to have involved Berylson, with the Range Rover leaving the road, rolling over into a ravine and coming to rest against a tree.

The 70-year-old male driver, who had to be cut out of the vehicle, was pronounced dead at the scene, and the crash continues to be investigated. The PA news agency has contacted the Falmouth Police Department for further clarification.

Berylson, who attended Harvard Business School and Brown University, first became involved with Millwall in 2006 and helped them become established in the Championship, finishing last season just outside the play-offs.

Tributes flooded in from around English football following the news, while the club have made a book of condolence available at The Den for any supporters wishing to pay their respects, while messages can also be left online.

Berylson is survived by wife Amy and three children Jennifer, James and Elizabeth.

In a tribute on the club’s official website, chief executive Kavanagh said it was “unquestionably the hardest thing I’ve ever had to write in my life” as he reflected on the “best club owner I have ever worked with”.

Kavanagh wrote: “What he did for Millwall over so many years was both extraordinary and exemplary. He trusted his staff to get on with the task at hand, but was always unwavering in his support in so many ways.

“John’s endless passion for Millwall was infectious. He was so incredibly dedicated to the club and year after year showed remarkable energy and drive to keep us progressing on and off the pitch.

“There have been ups and downs, sure, but in my view many more of the former, and as we know John enjoyed nothing more than to light up a big cigar in celebration of a famous win, promotion, or other deserving achievement.

“His regular visits to The Den became increasingly memorable as the support for him from the fan base grew further with every passing season.

“He loved the time he would spend walking the perimeter of the stadium to speak to supporters, and his lap of honour before the final game of the season – in hindsight an even more profound moment now – was amazing to witness.

“I feel so desperately sad for John’s family and our thoughts and prayers are with them at what is just such a devastatingly cruel time.”

Kavanagh confirmed Millwall’s squad would remain out in Spain to continue pre-season preparations and would visit The Den to pay their respects to the late chairman on their return.

Lions boss Gary Rowett said: “One of the players mentioned they had never heard a bad word said about John. I think that pretty much sums up what an amazing individual he was.

“All our thoughts go to his family, to his wife Amy and his children and grandchildren. Not only is it devastating news the last 24 hours for anyone who knew John, it’s very hard to comprehend just something of that magnitude.

“The first thing that strikes me is that I remember many conversations about players and matches and things he wanted to try to do to move the club forward and he’d often be having a conversation with one of his grandkids in the background.”

Rowett added in a video on the club’s social media accounts: “He would always ring me after games, he’d ring me a couple of times in the week just to ask how things were going.

“The skill that John had was incredible, he’d always try to make you feel better if you’d lost a game or something had happened.

“He’d always try to support and make it feel like there was a way out of it, there was a route out of it and there was a strategy to move forward. That showed his compassion, that showed his love for the club.

“It’s so difficult to comprehend, for me certainly, Millwall without John Berylson, because he was the figurehead, he was the inspiration and just a tremendous, tremendous owner and chairman.”