The International Tennis Federation has confirmed the American player Wayne Odesnik has been banned from the sport for 15 years following a second doping violation.
The 29-year-old, who was sanctioned for two years in 2010 for possession of human growth hormone, was found to have taken prohibited substances, including an anabolic steroid, after submitting out-of-competition urine samples in December 2014 and January this year.
The 15-year ban means Odesnik will not be eligible to return until January, 2030.
He had reached 77th in the world in 2009, but is currently ranked 267th.
The tests were carried out by the Tennis Anti-Doping Programme and US anti-doping body USADA.
"This case featured extensive co-operation between the ITF (on behalf of the programme) and USADA, including information sharing, use of the expertise of each organisation and a consolidated approach to the results management process," a statement said.
"These contributions are hereby recognised and held up as an example of the benefits of cooperation between Anti-Doping Organisations."
Odesnik was stopped by Australian customs officials and found to have eight vials, each containing six milligrammes of the performance-enhancing substance HGH, in his baggage.
The former top 100 player always denied taking HGH and his two-year ban was cut to 12 months after he gave "substantial assistance" to the ITF.
His results at this year's Happy Valley Challenger event, Australian Open and Maui Challenger event will be disqualified and the ranking points and prize money forfeited.