He came through the Exiles' academy and made his senior debut in 2020.

"It's obviously been a tough couple of months for everyone involved with London Irish," said Joseph.

"I just wanted to thank all the fans, coaches, and staff for their time and help in my career so far."

Chawatama, 30, joined London Irish in 2017 and made 18 Premiership appearances for the club last season.

The Zimbabwe-born front rower also played at London Scottish and London Welsh earlier in his career.

Cunningham-South, 20, joined the Exiles' Academy in 2022.

The forward, who can play at flanker or number eight, made his senior debut in May 2022 and went on to make 19 Premiership appearances last season, scoring three tries.

He has also represented England in the Under-20 Six Nations in the past two years and has been named in the squad for the upcoming U20 World Championships.

Newly appointed Quins director of rugby Billy Millard said he was "pleased" to welcome Joseph, Chawatama and Cunningham-South to the club and provide them with an opportunity to remain in the Premiership.

Meanwhile, Chawatama said in a statement:

"London Irish will always have a special place in my heart.

"I am so grateful for the six years I spent at the club, and will forever cherish the memories made with players, staff, and fans."

Cunningham-South added to the Quins club website:

"I'm excited to be starting a new opportunity at Harlequins and extremely grateful for the chance to join the club.

"I want to thank everyone at London Irish for the special memories and support."