Pakistan's ambassador to US Husain Haqqani on Saturday said he's not behind the secret memo which asked for US help to avoid a military coup and is ready for probe.

President Asif Ali Zardari has summoned Haqqani to Pakistan. Haqqani is likely to arrive in Islamabad on Saturday.

Haqqani also met with US special envoy for Afghanistan and Pakistan Marc Grossman before departing for Islamabad.

Haqqani had on Friday denied allegations that he was in any way linked to the memo and said he's ready for a probe.

Meanwhile, Pakistan-American businessman Mansoor Ijaz maintained he has proof to show that Haqqani got him to hand the memo to the US military chief Admiral Mike Mullen.

Haqqani, who denies he was behind the memo, tweeted on Saturday he was heading to the ”motherland”. Officials confirmed his return.