A team of the Anti-Drug Smuggling Unit searched the 27-year-old's home in Port Louis and found 22 doses of heroin and a further one gram of the drug.
Equipment used in the preparation and packaging of heroin, including razor blades and scales, were also seized.
Leopold is the first-choice goalkeeper for Mauritius Professional Football League champions team ASPL 2000.
He was also the reserve goalkeeper for the national team during the last Africa Cup of Nations qualifying campaign.
Leopold helped ASPL 2000 to win the Charity Shield on Saturday on Rodrigues Island where they beat Pamplemousses SC 1-0.
As the news of his arrest broke, some people gathered outside Leopold's home to prevent the ADSU from taking him to police custody.
According to information gathered by the BBC, the police had been tracking Leopard closely for some time and gathering intelligence.
A provisional charge of drug dealing has been lodged against him.
Both the Mauritius Football Association and ASPL 2000 refused to comment on the issue.

The addition of Permian, who was successful in the Dante Stakes at York, and last week's Goodwood winner Khalidi, means the total purse for the Classic on 3 June will be £1.625m.
The John Gosden-trained Cracksman is the favourite.
Cracksman beat Permian in the Derby Trial in April.
Meanwhile, trainer John Jenkins has defended his owner's decision to run 1,000-1 outsider Diore Lia, where she will be ridden by apprentice Gina Mangan.
Diore Lia has made just two competitive appearances to date, beating only one rival on her Epsom debut late last month before finishing down the field at Lingfield.
Owner-breeder Richard Aylward is keen to let his filly take her chance to generate publicity and funds for Great Ormond Street Children's Hospital.
"If I didn't run her, someone else would. The owner is keen to run her and has set up a charity. He's there for the big day," said Jenkins.
"I had a runner in the Derby a long time ago. That was an outsider as well and it didn't finish last.
"Has there ever been a 1,000-1 winner of the Derby?"

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27 October 2014 Last updated at 07:50 GMT
It was held earlier this month in Hunan province, in a mountain range thought to have inspired the floating mountains of Pandora in the Hollywood blockbuster film Avatar.
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Ajinkya Rahane became the fifth Indian to score centuries in both innings of a Test match as they declared on 267-5.
In reply, captain Hashim Amla (23 not out) took 46 balls to score a run, as South Africa made 72 in as many overs.
A 300-plus target has been reached just once on Indian soil, when the home team struck 387-4 to defeat England in 2008.
India resumed 403 runs ahead on 190-4 but skipper Virat Kohli added only five runs to his overnight 83 before a low Kyle Abbott delivery trapped him leg before to end the only century partnership of the series at 154.
Rahane, the only centurion of the series, was not to be denied another hundred, however.
The 27-year-old slog-swept Imran Tahir over mid-wicket for his second six of the innings and flicked Dean Elgar for another to move into the 90s.
He joined Vijay Hazare, Sunil Gavaskar (three times), Rahul Dravid (twice) and Kohli as the only India batsman to reach three figures twice in the same Test match.
South Africa blocked resolutely after left-hander Elgar was caught at slip in the fifth over, with India spinner Ravi Jadeja conceding only 10 runs from his 23 overs.
The usually destructive AB de Villiers maintained the team tactic, using 33 balls to score his first run.
His partnership with the captain did not produce a single run in the first 10 overs, but both batsmen survived to retain their team's hopes of avoiding defeat.
A 3-0 series victory for India would put them second in the world rankings behind the South Africans, who will lose top spot if they lose their next Test series at home to England, which begins on 26 December.
Mauritius international goalkeeper Joseph Kinsley Steward Leopold has been arrested for drug dealing.
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