ANKARA (AFP) - A massive statue of a "Transformers" style robot has gone on display in Ankara not, as some of residents suspected, as an elaborate April Fool's joke but erected by the city's mayor.

The mass of metal and polyester, which now towers over a busy road junction in the centre of the Turkish capital, went up on Thursday to promote the new Anka theme park, which mayor Melih Gokcek is having built despite a court injunction over complaints it breaks city planning rules, local press reported.

Gokcek, who has been mayor of this city of five million people since 1994, is one of the more colourful members of the ruling Justice and Development Party (AKP).

Turkish prosecutors last month launched an investigation into both him and Deputy Prime Minister Bulent Arinc after the two politicians traded angry accusations as a row within the ruling party widened.

Public prosecutors in Ankara were looking into Arinc on charges of misconduct and covering up a felony while they accused Gokcek of embezzlement and misconduct, private Dogan news agency reported.

Nicknamed "Mad Melih" by his detractors, the mayor had promised voters ambitious projects such as the theme park, with giant replicas of dinosaurs and robots, as well as a channel to "bring the Bosphorus in Ankara," an arid Turkish city.

The giant robot statue, resembling something out of the US Transformers sci-fi film series, did not impress all Ankara residents.

Twitter user "Brgn" called it nothing but a "late April fool's joke".