Flamengo have warned Arsenal to take them seriously with Pablo Mari's move to London now in limbo.

The Daily Mail says a Flamengo director has claimed Arsenal moved the goalposts in the deal to bring Mari to the Emirates, with the move now in serious doubt.

Mari arrived in London on Saturday for his medical after Arsenal technical director Edu Gaspar had agreed a deal with Flamengo to sign him on loan with view to a £7.5m transfer.

No problems were anticipated but the player is now back in Brazil after a late hitch.

A Flamengo director said: "We expect him at Ninho do Urubu this afternoon (to start pre-season). We had agreed to sell him for a fee, he arrived in London, Arsenal changed (the terms). Flamengo is a serious club."

Arsenal sources say Mari, 26, a former Manchester City centre back, had his medical and was set to sign with friends even congratulating him on his move but negotiations have now stalled at the final stage.

A disappointed Mari is now heading back to Rio de Janeiro. Negotiations are ongoing between Flamengo and Arsenal though the Gunners are also having to consider new targets.