The logo of Swiss pharmaceutical company Novartis is seen on its headquarters building in Basel, Switzerland October 27, 2015. REUTERS/Arnd Wiegmann/File Photo

ISTANBUL/ZURICH (Reuters) - Turkey’s investigation into Novartis is “ongoing”, a Turkish health ministry official told Reuters on Thursday, after the Swiss drugmaker said last week it was not under investigation over bribery allegations in Turkey.

The Ankara chief prosecutor’s office had said in April it was investigating the Turkish unit of Novartis after allegations were made that the company benefited from bribery.

Novartis said last week that it had determined the allegations were unsubstantiated and was not aware of any government authority investigating it. It said it considered the matter “closed”.

However, an official at Turkey’s health ministry in Ankara told Reuters that an investigation into Novartis was still “ongoing”. The official declined to give further details.

In Switzerland, a Novartis spokesman said it considered the matter closed and is no longer seeking information from Turkish authorities.

It maintains the allegations were “unfounded” and based on a past complaint.

Reuters reported in March that an anonymous whistleblower accused the company of paying bribes in Turkey through a consulting firm to secure business advantages worth an estimated $85 million.