Novartis said it would take "fast and decisive action" should an investigation into alleged bribery in Greece find that its managers engaged in unethical or illegal conduct.

The Basel-based company is in the midst of a bribery probe in which Greek prosecutors in early 2017 raided its offices in Athens.

Greece's Prime Minister Alexis Tsipras on Monday urged parliament to investigate the case.

Under Greek law, only parliament can investigate the role of ministers and lawmakers in a case, if it decides to do so.

Novartis said in a statement that while it was aware of reports of the investigations by both Greece and U.S. authorities, it had not received formal allegations from Greek authorities nor was it aware of an indictment.

"While Novartis continues to cooperate fully with the Greek and U.S. authorities, we have also been conducting our own comprehensive internal investigation," the company said.

"We are determined to fully understand the situation and accept responsibility for any actions that fell below our high standards of ethical business conduct. If any wrongdoing is found we will take fast and decisive action and do everything possible to prevent future misconduct."

Last week, Greek prosecutors referred the case to parliament. The house will decide whether to investigate if conservative and socialist politicians are found to have been involved in alleged bribes by Novartis to doctors and public officials.

Politicians, who have been named in parliament, have strongly denied the allegations, calling the claims a fabrication and a witchhunt by Tsipras' leftist-led government seeking to discredit them, a little over a year before scheduled elections in the country.

Tsipras' Syriza party and its coalition ally, the right-wing Independent Greeks are in favor of such a probe. Their parliamentary groups submitted an official request for a committee to be formed to conduct an inquiry.

"We will do everything we can to reveal the truth," Tsipras told his Syriza party lawmakers in parliament. "Nothing will stay secret, nothing under the carpet."

Tsipras, in charge since the height of Greece's financial crisis in 2015, has promised to crack down on corruption which he often blames on his predecessors. His party is trailing conservative New Democracy in opinion polls.

Greek prosecutors have been conducting an inquiry for more than a year, in which a number of individuals testified under a witness protection scheme. According to court officials, their investigation into the role of non-politicians is ongoing.

Novartis said in its statement that publicity surrounding the case, "appears driven in large part by the selective leaking of portions of a confidential and preliminary investigative file."

The company also said there were "many sensational and unfounded claims in a politicized debate."

Novartis has faced other investigations in recent years. Last year, for example, it was fined $49 million by South Korea for offering doctors kickbacks.

Additionally, a separate federal U.S. Department of Justice lawsuit against Novartis is ongoing.

(Additional reporting by George Georgiopoulos in Athens; Editing by Jane Merriman and Adrian Croft)

By Renee Maltezou and John Miller