Turkey has launched an investigation into alleged drug use in the country, with an operation targeting a number of celebrities.

During the probe by the Narcotics Crimes Bureau, 19 people - including actresses Berrak Tuzunatac and Demet Evgar, and singer Hadise Acikgoz - were summoned for questioning and blood sample collection.

Music and television stars, as well as social media influencers, have denied all the accusations against them through their lawyers. No formal charges have been filed.

The move has sent shockwaves through Turkey's entertainment industry. It comes against a backdrop of growing concerns in the country over freedom of speech.

Turkish media are reporting that the celebrities were summoned on Wednesday and were expected to be released after blood tests.

Turkish authorities have not publicly commented on the issue.

According to Turkish law, drug possession for personal use carries a prison term of up to five years.

However, courts can order treatment or probation for first-time offenders, avoiding prison sentences.

Opponents of Turkish President Recep Tayyip Erdogan point to a wider crackdown on artists, media and opposition figures in the country in recent months.

In September, an investigation was launched against musician Mabel Matiz over alleged "obscenity" in one of his songs. He now faces up to three years in jail.

The same month, prosecutors said they would seek one-year jail terms for Turkey's popular girl band Manifest for "indecent behaviour" in their dance routines.

Last week, prominent journalist Fatih Altaylı went on trial, accused of making "threatening" remarks against Erdogan. Altaylı - who denies any wrongdoing - now faces a minimum five-year prison sentence.

In March, protests erupted in the country after authorities detained Istanbul Mayor Ekrem Imamoglu, just days before he was due to be selected as a presidential candidate for elections set for 2028.

Imamoglu is seen as one of Erdogan's strongest political rivals.

Erdogan's government denies the crackdown allegations.