The four touts, who stand on Bangla Rd soliciting passers-by to enjoy the services of their venues, were questioned by Patong Police, with Tourist Police officers present.
Lt Col Kittisak Sommat, Chief of Investigation at Patong Police Station explained that in reporting the incident to the embassy officials, Ms Mukhieva said that they were attacked by four wearing uniforms who had robbed them of B8,000.
Patong Police have yet to reveal any further details about the attack, which was first reported yesterday.
The American man injured in the attack has been identified as Rakkan Gassim Algassim, 35, from Pennsylvania. He was accompanied by Russian national Alena Mukhieva, 24.
Mr Algassim was attacked about halfway along Bangla Rd in front of a bar that was closed at the time of the attack. Police were first alerted to the incident at 3:30am.
A bar staffer who arrived at the scene soon after the attack said that the incident involved Mr Algassim fighting with another foreigner. She provided no further details about any other people involved in the incident.
The staffer, who asked not to be named, said that Mr Algassim refused help from people who came to render assistance, and held tightly onto a black bag he was carrying.
With Mr Algassim refusing help, Ms Mukhieva said she was going to order a taxi to pick them up.
On hearing this, the staffer said she decided to call Kusoldharm Foundation rescue workers to arrive and provide assistance.
It is not clear whether any police were in the area when the attack happened.
Mr Algassim suffered multiple cuts and bruises to his face in the attack. He also suffered a deep laceration to the middle finger on his left hand which required medical treatment at Patong Hospital.