Police have arrested eight students and backpackers and seized one kilogram of drugs and more than $200,000 in cash after a five-month investigation into an alleged Sydney drug ring.

Strike Force Oramzi officers arrested a 25-year-old Thai woman and seven French men, aged 24, 26, 27, 28 and 44 and two aged 23, during five searches at Haymarket, Darlinghurst and Tamarama about 7am yesterday.

All eight people are believed to be in Australia on tourist, student or working visas.

Police arrested eight people, seized one kilogram of drugs and $235,000 as part of an investigation into a Sydney drug ring yesterday. Picture: 9NEWS. (9NEWS)

Four of the eight people were refused bail and charged with a spate of crimes including the supply of illict drugs and dealing in the proceeds of crime. Picture: 9NEWS. (9NEWS)

All eight were either students or backpackers in Australia on tourist, student or working visas. Picture: 9NEWS. (9NEWS)

Police also seized $235,000 in the raids.

Strike Force Oramzi was established in November last year to investigate the distribution of the illict drugs MDMA, cocaine, LSD, ketamine and cannabis.

Four of the arrested men have been charged with offences including supplying prohibited drugs, knowingly dealing with the proceeds of crime and directing or participating in criminal activities.

Four men who appeared in court today did not apply for bail before it was formally refused. Picture: Supplied. (Supplied)

The men are expected to reappear in court at the end of the month. Picture: Supplied. (Supplied)

Florian Chamon, 23, Mourad Hannachi, 44, Damien Masset, 24, and Kevin Bianchi, 26 all appeared at Parramatta Local Court today, did not apply for bail and it was formally refused.

The 27-year-old was also charged with possession of a prohibited drug and granted conditional bail to appear before Downing Centre Local Court on April 26.