Two Russian TV presenters have admitted to pranking Sir Elton John by posing as Vladimir Putin during a phone call about gay rights, according to reports.

The Rocket Man singer posted a picture of Putin on his Instagram account on Tuesday night to thank the president for "reaching out and speaking via telephone".

The star's publicist, Gary Farrow, confirmed the pair had been in contact but a spokesman for Putin later denied a conversation had taken place.

The pranksters, Vladimir Krasnov and Alexei Stolyarov - better known as Vova and Lexus - claimed responsibility for the call in an interview with Russian media outlet Komsomolskaya Pravda, saying it was easy to get in touch with Sir Elton, 68.

The musician publicly offered to talk with the Russian leader after meeting with Ukraine's president Petro Poroshenko at a conference to lobby him about LGBT rights.

Vova and Lexus said it seemed Sir Elton was "waiting for that call, so immediately believed in the reality" of the conversation.

The duo claim the singer responded to the 11-minute call, which will air in full on state-owned Channel One during the Evening Urgant show tonight, by saying: "Thank You. You made my day. This day, and the conversation was the most wonderful and beautiful in my life."

Sir Elton, whose real name is Reginald Dwight, had criticised the Russian president's "ridiculous" stance on gay rights and accused Mr Putin of saying "stupid things" in reference to his warning to gay people travelling to the Winter Olympics to "leave the children in peace".

Russia also passed a law banning homosexual "propaganda" among children in June 2013, sparking an international outcry.

The singer, who has two young sons with husband David Furnish, has been outspoken on the issue of gay rights before, most recently when, earlier this year, he temporarily boycotted Dolce and Gabbana after the fashion designers called children conceived by IVF "synthetic".