Ankara, Dec 26 (IANS): Turkey's Environment and Urban Planning Minister Erdogan Bayraktar Wednesday resigned over a major graft probe and called on Prime Minister Recep Tayyip Erdogan to quit, media reported.

Bayraktar joined Interior Minister Muammer Guler and Economy Minister Zafer Caglayan who announced their resignations earlier Wednesday, Xinhua reported citing a Dogan news agency report.

The environment minister told reporters that he was resigning not only as a minister but also as a parliamentary deputy of the ruling Development and Justice Party (AKP), according to the report.

While Bayraktar's son was briefly detained in the graft probe, Guler and Caglayan's sons, along with 24 others, have been in police custody since Dec 17, the first day of the investigation.

Meanwhile, the US embassy in Ankara Wednesday issued a statement refuting involvement of the US in the graft probe and warned that it would jeopardise the Turkish-US relations.

"Allegations in some media outlets that target the American embassy staff do not reflect the truth," the statement said.

On Dec 17, Turkey was rocked by the country's largest ever bribery investigation, in which sons of four cabinet members were detained and a huge amount of money was seized by authorities in their houses.