The Sun newspaper said Li Cai Ling, a resident of the southern town of Muar, which saw intense air pollution at the weekend died on Sunday with a medical report blaming the polluted air.
Singapore initially bore the brunt of Southeast Asia's worst smog crisis for years with pollution reaching record levels last week. Favourable winds have since cleared the air over the city state but southern Malaysia remains choked by smoke.
The smog has eased but continued to hang over some areas including the capital Kuala Lumpur today.
The situation has also forced newly-promoted English Premier League side Cardiff City to cancel a Malaysia visit that was set to begin this week.
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The club said in a statement posted on its website yesterday that it has abandoned the scheduled week-long trip to Malaysia -- home of its billionaire owner Vincent Tan -- "due to the current poor air quality in the region".
Several team representatives including manager Malky Mackay and forward Craig Bellamy were to leave for Malaysia tomorrow for a visit intended to promote the club to the country's football fans.
The air pollution has also forced the cancellation of other sporting events in Malaysia including a marathon in Kuala Lumpur and a national-level competition for disabled athletes.
Haze is an annual problem during drier summer months, when westerly monsoon winds blow smoke from forest fires and slash-and-burn land-clearing on the huge Indonesian island of Sumatra, which lies across the Malacca Strait.
Malaysia's environment minister travelled to Indonesia Wednesday morning to meet his counterpart in the hopes of resolving the problem, which earlier sparked a testy exchange between Indonesia and Singapore.