Sitting MP from Punjab Harinder Singh Khalsa, who was suspended from the AAP, joined the BJP Thursday.
Fatehgarh Sahib MP Khalsa joined the party in the presence of Union Finance minister Arun Jaitley.
Khalsa, who belongs to the SC community, had won the 2014 Lok Sabha polls on the Aam Aadmi Party's ticket, but was suspended from the party in 2015.
He started his political carrier with the Bharatiya Janata Party's ally in Punjab Shiromani Akali Dal (SAD).
The BJP is in alliance with the SAD in Punjab and will contest on 13 Lok Sabha seats in the state.