In a Diu Indo-Portuguese relative clause, the relativized element is almost always expressed by the relative particle ki, but there is a host of other elements (formally equivalent to interrogative pro-forms) which sometimes function as relative particles sensitive to the epistemic domain of the relativised element (e.g. whether it is a human referent, a location, a manner expression, etc.).
With respect to direct object relative clauses, the relevant relativizers are ki, kẽ and kwɔl. The relative particle ki is by far the most common, used for all kinds of referents; kẽ is reserved for human referents and, although quite rare as a relativizer, is otherwise very common as an interrogative pronoun meaning 'who'; kwɔl, even rarer as a relativizer (but common as an adnominal question word meaning 'which'), has been recorded with both human and non-human referents.
Of the three relativizers under analysis, the only one which fits our definition of a relative pronoun is kẽ, as this is the only one which admits dative/accusative case-marking (although it may also shun the dative-marking preposition altogether). This fact is not entirely surprising, given that, in Diu Indo-Portuguese, animate referents are the only ones requiring accusative case-marking in direct object position. Whenever a relative particle is selected (i.e. ki or kwɔl), no case-marking occurs, even though these can stand for an NP which would otherwise require overt attributions of case.
The relative construction consisting of a relative particle and a resumptive pronoun is rather marginal and encountered only in elicitation.
Source: Cardoso 2009: 244
Source: Cardoso 2004-2008
Source: Cardoso 2009: 243
Source: Cardoso 2004-2008