Kumar is in the national capital in connection with Janata Parivar merger developments.
Five days after being kidnapped, doctors Pankaj Gupta and Shubhra Gupta today returned home in Gaya town after being freed in Lucknow, Bihar Police chief P K Thakur said.
Official sources said Kumar thanked Yadav for actively cooperating in the release of the couple and hoped such cooperation would continue as criminals from one state often take shelter in another and many times work in tandem.
The two had been abducted from Barachatti area of Gaya district on Friday while they were returning to Gaya after attending a wedding in Giridih in Jharkhand.