Opposition journalist Khim Sambor, who wrote for Moneaksekar Khmer, was killed July 11.

The Ministry of Interior has formed an "investigation committee" to determine how to move forward in the murder case of opposition journalist Khim Sambor, an official said Tuesday.

The ministry has received a letter from the FBI, but the investigation committee will decide how the FBI can help, said Interior Ministry spokesman Lt. Gen. Khieu Sopheak told VOA Khmer.

The ministry has requested the help of the FBI, but US officials said this week they were still waiting for a specific responses on how the US agency might help the investigation.

"We're still waiting," former US ambassador Joseph Mussomeli told reporters before leaving the country Monday. "We are still awaiting from the police a list of exactly what they think they need from us."

"We have very good ideas of what they need from us, and we are sharing that as well," Mussomeli said.

The FBI could help, for example, through the use of a sketch artist or forensic specialists, US Embassy spokesman John Johnson said Tuesday.

Khim Sambor was shot dead in Phnom Penh on July 11, along with his son, two weeks ahead of national elections. No suspect has been arrested.