The senior police official told Sri Lanka Mirror that the complaint was over a revelation by Namal Kumara about a plot by a DIG to assassinate the president and former defence secretary Gotabhaya Rajapaksa.
The CID has already obtained a statement from the ex-defence secretary and is due to record a statement from IGP Pujith Jayasundara as well.
Jayasundara will be asked to explain with regard to the provision of two light machine guns to the TID among other matters.
According to police headquarters sources, this week will be important for the investigation.
Namal Kumara alleges the murder plot aims to obtain personal gains from prime minister Ranil Wickremesinghe and the IGP.
After making the allegation first at a media briefing in Kandy, where he made references to the IGP too, Namal Kumara also complained to the National Police Commission.
The DIG in question, Nalaka de Silva, will also be summoned to the police headquarters for questioning.
Meanwhile, reports say the president and the PM had a special meeting on October 12 and discussed the delay in this investigation.
Details of what has transpired there are not reported in the media.