New Delhi - India has ordered a probe and issued a show-cause notice to the US-based Continental Airlines as to why its staff frisked the country's former president APJ Abdul Kalam, officials said Tuesday.

India's Civil Aviation Minister Praful Patel told parliament that his ministry had demanded the airline explain the frisking of Kalam in violation of guidelines.

Patel said he would not only take action against the airline, but would also speak to the External Affairs Ministry to raise the issue diplomatically.

"This act of frisking the former President is absolutely unpardonable and beyond the scope of laws of our country," Patel said after parliament was in an uproar over the "humiliation" meted out to Kalam, whom they described as a national hero.

Under domestic protocol, presidents and former presidents are on the VVIP list and are exempted from security checks and searches.

But Kalam was subjected to a full body check and asked to remove his footwear by ground security staff of Continental Airlines at the airbridge at the Indira Gandhi International Airport before boarding the flight to the US on April 24 this year.

The matter came to light on Tuesday after Kalam's aides told local news channels about the incident.

Indian lawmakers condemned the incident and said until the personnel involved in the incident were taken to task, the airline's flights should be suspended.

Opposition Bharatiya Janata Party leader Arun Jaitley described the incident as "outrageous" and said "it is an issue that has put the whole nation to shame."

A spokeswoman for Continental Airlines described the search as a "normal security procedure," according to the PTI news agency.

"There is no special rule for VIPs and VVIPs. This is the process the airline adheres to," the spokeswoman, identified only as Aparna, told the PTI.

She said Kalam was "very cooperative" and "happily underwent the entire process."

Kalam, India's president from 2002 to 2007, is highly popular across India. An eminent nuclear scientist, he is known as India's "missile man" for his work on development of indigenous ballistic missile and space rocket technology.(dpa)