Leaked recordings of the Turkish prime minister and his son allegedly discussing how to hide large sums of money are fake, the premier's office said, as the government grappled with the latest fallout from a damaging corruption probe.
"The recordings... are the product of an immoral montage and completely untrue," Erdogan's office said in a statement late on Monday.
"Those who created this dirty setup targeting the prime minister of the Republic of Turkey will be held accountable within the law."
The phone conversations, posted on YouTube, allegedly reveal Prime Minister Recep Tayyip Erdogan asking his son Bilal to turn millions of euros (dollars) in cash stashed at several houses into "zero".
The leaked discussions, which could not be independently verified, were said to have taken place on December 17, the same day that a high-level corruption probe erupted implicating key Erdogan allies.
In one conversation, Erdogan can supposedly be heard briefing Bilal about the police raids, which saw top businessmen and the sons of former cabinet ministers detained on allegations of bribery, gold smuggling and illicit dealings with sanctions-hit Iran.
The prime minister has blamed his ally-turned-rival, US-based Muslim cleric Fethullah Gulen, for instigating the graft probe, accusing him of seeking to create "a parallel state" in Turkey.
Erdogan has retaliated by dismissing or re-assigning hundreds of police officers and prosecutors involved in the investigation.
In a sign of further tensions, the Turkish government on Monday said thousands of influential people, including the premier, cabinet ministers and journalists, had been wiretapped by Gulen supporters in the police and the judiciary.
After the recordings were leaked online, Erdogan held an emergency meeting with his intelligence chief Hakan Fidan, as opposition leaders called for the government's resignation.
"The government has lost its legitimacy... and must resign immediately," Haluk Koc, a spokesman for the main opposition Republican People's Party, told a news conference late on Monday.
Devlet Bahceli, leader of the Nationalist Movement Party (MHP), said the alleged recordings were "dazzling", and demanded that the prime minister be brought to justice.
Erdogan was due to address a weekly meeting of his Justice and Development Party (AKP) in parliament later on Tuesday.
The political tensions of the past months have battered Turkey's financial markets, with the lira and stocks tumbling.
The lira stood at 2.2101 to the dollar and 3.0402 to the euro on Tuesday morning. The Istanbul stock exchange BIST 100 declined by 2.41 percent to reach 62 639.68 points.
Last month, Erdogan rejected allegations that his son was involved in the corruption scandal, which has thrown up the serious challenge yet to his 11 years in power ahead of key local elections in March. - Sapa-AFP