Graeme McDowell has been suspended by LIV Golf for one tournament for violating the circuit’s anti-doping policy.
The Saudi-funded series said, external the 45-year-old used “a decongestant medicine that included a banned substance”.
The offence by the Northern Irishman occurred during LIV Golf Nashville in June and he has also been fined 125,000 US dollars (£98,000).
“Ahead of LIV Nashville, I was struggling with severe congestion that was affecting my sleep,” said McDowell, who won the US Open in 2010.
“In an effort to manage it, I used a generic nasal decongestant without realising it might be on the banned list.
“As a professional golfer, I understand the importance of checking all medications and the option to apply for a Therapeutic Use Exemption (TUE).
“Unfortunately, I did not think to do this due to the over-the-counter nature of this medicine and I deeply regret the oversight. I fully accept the sanctions imposed by LIV.”
Read More: Graeme McDowell suspended by LIV Golf for anti-doping offence