Randhawa ji,
It is not only this Guru that claims Guru Nanak was a follower of Bhaghat Kabir, but many Vaishno's within our own Sikh paanth that claim this.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/bhagats/27429-kabir-and-guru-nanak-dev-ji.htmlReference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=27429
What they do not realise is that many, many shaloks of Kabir were left out of Bani by our Guru's, because they did not sit well with the message of Sikhi.
Regards
Randip Singh