Inspector-general of police (IGP) Khalid Abu Bakar has instructed his officers to probe a Twitter user who had called him Prime Minister Najib Abdul Razak's "dog".

The Twitter user carried the same name as Gerakan Youth chief Tan Keng Liang but the account appeared to be an impersonator who has misspelled the handle as @tankenglaing.

Tan's real Twitter account is @tankengliang.

The fake Twitter account also used Tan's account photograph.

"PCRIC (Police Cyber Investigation Response Centre), please track this Twitter handle below and take the necessary action," tweeted Khalid.

Khalid also reproduced the offending post, which commented on the Altantuya Shaariibuu murder case.

The posting referred to Khalid by his Twitter handle "KBAB51" and called him a dog who followed Najib's orders even though it was "haram and against the law".

Altantuya's ghost resurfaces

The Twitter post was one of several tweets by the impersonator that derided Khalid over the 2006 Altantuya murder case.

Two of then deputy prime minister Najib Abdul Razak's bodyguards were convicted for the murder.

Azilah Hadri is awaiting death sentence while Sirul Umar Azhar has fled to Australia.

The murder remains a mystery as the motive was never established.

Najib has vehemently denied any links to the murder, and repeated the claims yesterday after Al Jazeera aired a documentary revisiting the murder's troubling aspects.

PCIRC @PDRMsia sila kesan twit handle dibawah dan ambil tindakan sewajarnya. pic.twitter.com/RtgId5Lr89

— Khalid Abu Bakar (@KBAB51) September 12, 2015

#altantuya ..setahu saya anjing @KBAB51 ikut arahan tuan @NajibRazak walaupun ia adalah haram dan melanggar undang undang

— Tan Keng Liang (@tankenglaing) September 11, 2015