MEXICO CITY –  What had seemed to be another attack on a tourist in Acapulco appeared to turn into something a bit more involved but equally sinister on Monday, when the company of a Belgian businessman shot to death in the Pacific resort over the weekend said he had received death threats following a legal dispute with a former business associate.

The killing of Belgian Jan Sarens outside a shopping center on Saturday cast a pall over this once-glittering but now violence-plagued resort, which is preparing to host the Mexican Open tennis tournament this week. It was the second violent attack involving foreigners in Acapulco in less than three weeks. On Feb. 4, a band of masked gunmen invaded a beachfront home and raped six visiting Spanish women.

Sarens' company, the Belgium-based Sarens Group, said in a statement Monday that he had received death threats, after he filed a lawsuit against a former Mexican associate, Gruas Industriales Ojeda.

Both companies are involved in the industrial crane business, and the dispute apparently involved the ownership of cranes.

"A short while after the start of the activities in Mexico the Sarens Group became the victim of scams by their then partner, the Mexican enterprise Gruas Ojeda. This conflict led to a long judicial struggle, which was finally arbitrated in favor of Sarens, but the agreement has still not been executed," the Sarens Group said in a statement.

"After the Sarens Group had been able to recover a part of their material ... however this success was overshadowed by the fact that the ex-associate didn't keep to his refund obligations and the Sarens Group was forced once again to call in the help of the Mexican court. Within this situation death threats have been made against Mr. Sarens and the director of the Mexican group association," the company said.

Gruas Ojeda did not immediately respond to requests for comment on the case. Local media reported on a $9.8 million judgment against Gruas Ojeda in the case in 2011, but the Mexico City judiciary council was not immediately available to confirm the ruling.

Prosecutors in the southern state of Guerrero, where Acapulco is located, said Sunday they were looking into robbery or "personal revenge" as motives in the killing.

Sarens, 59, a longtime resident of Mexico City who was visiting Acapulco on the weekend, was found dead near his Mercedes-Benz convertible; the car was not stolen.

"The lines of probable investigation point to personal revenge or robbery," the state government said.

Acapulco has been plagued by drug-related shootouts, beheadings and killings in recent years, and officials have been quick in the past to rule out any involvement of drug cartels in crimes against tourists. One of Mexico's chief arguments to support it tourism industry is that cartels don't target tourists.

One of the first statement Acapulco's mayor made after the Spanish tourists were raped was that the crime didn't appear to be related to drug cartels.

In the end Sarens' killing may not have been either, but experts say the lawlessness and impunity created by the drug gangs has created an atmosphere in which other kinds of crimes can occur. Law enforcement is overwhelmed by violence, poor prosecution and public mistrust, to the point where Mexico's National Human Rights Commission estimates that only 8 percent of crimes are even reported, and only 1 percent are punished.

Law enforcement in Guerrero has been so weak that villagers in many towns of the state have started armed self-defense patrols to combat cartels and common criminals.

Alejandro Hope, a security analyst and former high-ranking official in Mexico's national intelligence agency, said "an atmosphere where impunity thrives is an environment that gives rise to all types of violence, in which people settle their differences outside of the law."