The family of an Orthodox Jewish scholar who drowned in one of Hampstead Heath’s bathing ponds have paid tribute to a “charming man who people loved to be near”.

Moses Grunfeld, 19, of Fairholt Road, Stoke Newington, entered the water in a section of the men’s pond which is out-of-bounds to swimmers, last Wednesday, the hottest day of the year so far.

The two friends he was with raised the alarm just after 5.30pm when he “vanished” from their sight, and dozens of firefighters mounted a desperate search supported by marine units, the police helicopter and volunteers.

His body was found at 11pm, 5ft underwater and 20ft from shore.

Speaking on behalf of his family, his 25-year old sister who does not wish to be named, said they are still in shock. “I think the word charming sums up his personality very well,” she said.

“He was the baby of the family, people just loved to be near him, he was amazing company, a very clever intelligent boy, very mature beyond his years and extremely friendly. We have had people of all ages coming over now to pay tribute to him, everyone felt as if they were his best friend, people 20 years older than him or younger than him felt so close to him.

“He had a friend who got married in New York – they didn’t have money for the expense of a wedding. He raised an abnormal amount of money and gave it to the friend to get married – he was the kind of boy that didn’t sit and wait for things to happen.”

Moses, a strictly Orthodox scholar, had flown home from university in Brooklyn, New York to spend Passover with his mother, and was supposed to return on Sunday.

It was initially thought the shock of the sudden temperature drop of the cold water may have triggered a cardiac arrest, but a scan indicated the cause of death was drowning.

His sister added: “There were so many people there who tried to help and do what they can. It went very fast from what I hear, they were saying one minute he was there, the next he wasn’t and there wasn’t anything anyone could do.”

Moses had one brother and five sisters, and their father passed away five years ago from cancer.

His sister added: “We are believers, we are Jewish and believe in God. We don’t understand it and obviously we would love to have Moses here with us, but we try and come to terms with it and believe it is best for him, and we will try and live as best we can without him.

“You could in such circumstances think what could we have done and what should we have done, is it our fault we let him go out?

“But if we say it’s in the hands of God and it’s what he would have wanted, rather than living with guilt and blaming.”