Prosecution on charges of murder of a mother who left two toddlers home alone where they starved to death began at Nanjing People's Procuratorate on Wednesday.

The bodies of the two girls, aged 1 and 2, were discovered at their home in Jiangning district, Nanjing, Jiangsu province, on June 21.

The 22-year-old mother, surnamed Le, had been missing for two months, according to prosecutors.

Le and her boyfriend, who both have a history of drug abuse, began living together in 2011. She became the sole guardian of the toddlers in February when their father, surnamed Li, was imprisoned on charges of providing shelter for drug addicts.

Le, who is three months pregnant, is currently under surveillance at a guesthouse. By law, women who are pregnant at the time of trial cannot be sentenced to death.