TAIPEI (Taiwan News) — Prosecutors are asking for a tough sentence for three suspects accused of the murder of a Thai-Taiwanese couple, including a pregnant woman, in June, reports said Friday (Sept. 9).

The men have been accused of killing the couple in New Taipei City before abandoning them in the trunk of their car near Taoyuan High Speed Rail Station. The motive for the crime was reportedly a dispute about debts.

Prosecutors in Taoyuan said Santi Supa-apiradeepailin, a man holding both Thai and Taiwan citizenship, recruited two other Thais, named Samart and Thanawat, to plot the death of the couple, who managed a brokerage agency for migrant workers, CNA reported.

Santi called the couple on June 8 to meet and discuss accounts at an office in New Taipei City’s Tucheng District during the evening. As they arrived, the two other Thai men attacked them and beat them to death with iron bars, prosecutors said.

After changing clothes, Santi drove the dead couple in their SUV to a parking lot near the Taoyuan station early on June 9 before boarding a flight to Thailand with his two accomplices. Police in the Southeast Asian country arrested the two men, while Santi gave himself up in Chiang Mai accompanied by relatives.

As the murdered wife was five months pregnant with twins and the killers showed no mercy, they should receive the toughest possible penalty, prosecutors said Friday.