The Charity Commission has defended itself from criticism by descendants of the artist JMW Turner that it allowed the Tate Gallery to spend £10m on "absolute rubbish".
The row began when trustees of the Tate, acting on advice from the commission, spent the insurance money from the theft of Turner paintings on modern art.
The gallery allocated only £1m of the £17m it received following the theft of the paintings, which have since been recovered to care of the Turner catalogue.
"The money should be used on something to do with Turner," said Jean Steward, whose great-grandfather was the artist's uncle. "He left these works to the nation."
Of contemporary artists Damien Hirst and Rachel Whiteread, whose work features in the Building the Tate Collection the gallery has purchased, she said: "Their work is absolute rubbish. It's not art at all."
The Charity Commission advised the Tate it had the authority to spend the Turner bequest after "long and complicated" discussions with both the gallery and the Attorney General involving the artist's will.
The Attorney General ruled that the legacy was part of the Tate's overall collection, not a separate entity, and that the trustees were free to decide how the funds should be used.
"The commission understands that Turner scholars and descendants feel very passionately about their area of expertise," said Antony Robbins, head of communications at the commission. "But we feel the right decision has been made and we are in full support of the Tate Gallery. The Tate still has the Turner paintings, so in many ways it is a happy result."
The remaining £6m insurance money will be spent on the long-term care of the collection generally, including research, conservation and improving access to the Tate's collection store in Southwark.
Sir Nicholas Serota, director of the Tate, said: "We are in a position to have both paintings returned and a sum of money that creates opportunities to acquire works for the collection."