Two men arrested over the slaying of Australian businessman Robert Ellis in Bali tried to halt officers using a machete and poison arrows.

Police tracked down two 24-year-old men, known by initials UR and DN and were attempting to arrest them when attacked.

Police spokesman Hery Wiyanto said police shot them both in the legs as they gave resistance.

"Police (were) forced to shoot them in their legs as they (fought) back using poison arrows and machete" said Hery.

Robert Kevin Ellis, 60, was found dead on October 21, his body bundled in plastic and dumped in a watery ditch by a Bali rice field.

At the time, Badung police chief Komang Suartana told 9NEWS his wife Noor Ellis was at home in their Bali villa when the killer she allegedly hired slashed her husband's throat in their kitchen.

Mr Komang said the slaying was allegedly a joint effort between Ellis' wife, two maids and one of their boyfriends.

It is understood money was a motive in the killing, but friends of Mrs Ellis later said she was independently wealthy.

Police spokesman Hery said today's suspects were arrested on Sumba Island at 5am (local time) today.