Forty-four-year-old Raja Bhaiya was sworn in by Governor B L Joshi at Raj Bhawan in the presence of SP supremo Mulayam Singh Yadav, Chief Minister Akhilesh Yadav and senior cabinet minister Mohd Azam Khan.
He would be allocated a ministry later.
The former Food and Civil Supplies Minister had to resign from the cabinet after being named by DSP Haq's wife Parveen Azad in the murder case in March.Though CBI gave clean chit to Raja Bhaiya, Azad had filed a protest application against it.
Talking to reporters after taking oath as Minister, Raja Bhaiya flayed the media for holding him guilty in the murder case "even before any probe was started".
"The media had held me guilty in DSP murder case before any probe was started. Now that I have been given clean chit by the CBI, they should review their working. I am thankful to SP supremo Mulayam Singh Yadav and Chief Minister Akhilesh Yadav for having faith in me," he said.
Eight criminal cases are pending against the MLA from Kunda.
Asked about which portfolio would be allocated to him, Raja Bhaiya said he would do his duty sincerely irrespective of the department he was given.
About the number of criminal cases pending against him, Singh said they were "courtesy BSP government".
When asked whether he was re-inducted as a minister in a "damage control" exercise after Muzaffarnagar riots to manage "Thakur" votes, Singh said, "As far as I know, Mulayam Singh's politics is not based on casteism."
When asked about his earlier statement that some persons conspired to include his name in the DSP murder case, Singh said let the name of "conspirators" be a secret. To a question whether it was Congress that conspired against him, Singh said, "May be".
There are a total of 59 ministers in the UP Cabinet and the upper limit is of 60 ministers.
At present, there are 22 Cabinet ministers including CM, six state ministers with independent charges and 31 state ministers.