The 24-year-old Prince, who has already had one meeting with Lieutenant Colonel Harry Fullerton, the Household Cavalry's commander, is set to be formally interviewed.

Even as the Prince has publicly apologised for calling one his colleague a ‘Paki’ in 2006, the military has initiated a probe, determined to deal with the matter in line with "normal Army procedures". Paki is a derogatory term for Pakistanis.

"The Army does not tolerate inappropriate behaviour in any shape or form," a spokesperson for the Ministry of Defence was earlier quoted by The Daily Telegraph as saying.

According to senior sources, it is likely the Prince, the third in line to the British throne, will be formally reprimanded over his remarks and made aware that the army has a zero-tolerance policy on racism, the daily said.

Even though the young Pakistani officer, Captain Ahmed Raza Khan, has not made a formal complaint, the publication of the tape by a British tabloid, in which Harry was filmed making the "racist" remarks, forced the Household Cavalry to begin an investigation.

According to British paper, General Sir Richard Dannatt, the head of the Army, was "disappointed and extremely cross" at the racist term used by the Prince.

A senior official said the row had done "immense damage" to attempts at attracting more Asians to the Army.