diff --git a/milli/src/documents/primary_key.rs b/milli/src/documents/primary_key.rs
index 79fd07048..1831a2dbc 100644
--- a/milli/src/documents/primary_key.rs
+++ b/milli/src/documents/primary_key.rs
@@ -1,15 +1,14 @@
-use std::borrow::Cow;
 use std::iter;
 use std::ops::ControlFlow;
 use std::result::Result as StdResult;
 
 use bumpalo::Bump;
 use serde_json::value::RawValue;
-use serde_json::{from_str, Value};
+use serde_json::Value;
 
 use crate::fields_ids_map::MutFieldIdMapper;
 use crate::update::new::indexer::de::{match_component, DeOrBumpStr};
-use crate::update::new::{CowStr, KvReaderFieldId, TopLevelMap};
+use crate::update::new::KvReaderFieldId;
 use crate::{FieldId, InternalError, Object, Result, UserError};
 
 /// The symbol used to define levels in a nested primary key.
@@ -230,45 +229,6 @@ impl<'a> PrimaryKey<'a> {
         Ok(external_document_id)
     }
 
-    /// Returns the document ID based on the primary and
-    /// search for it recursively in zero-copy-deserialized documents.
-    pub fn document_id_from_top_level_map<'p>(
-        &self,
-        document: &TopLevelMap<'p>,
-    ) -> Result<StdResult<CowStr<'p>, DocumentIdExtractionError>> {
-        fn get_docid<'p>(
-            document: &TopLevelMap<'p>,
-            primary_key: &[&str],
-        ) -> Result<StdResult<CowStr<'p>, DocumentIdExtractionError>> {
-            match primary_key {
-                [] => unreachable!("arrrgh"), // would None be ok?
-                [primary_key] => match document.0.get(*primary_key) {
-                    Some(value) => match from_str::<u64>(value.get()) {
-                        Ok(value) => Ok(Ok(CowStr(Cow::Owned(value.to_string())))),
-                        Err(_) => match from_str(value.get()) {
-                            Ok(document_id) => Ok(Ok(document_id)),
-                            Err(e) => Ok(Err(DocumentIdExtractionError::InvalidDocumentId(
-                                UserError::SerdeJson(e),
-                            ))),
-                        },
-                    },
-                    None => Ok(Err(DocumentIdExtractionError::MissingDocumentId)),
-                },
-                [head, tail @ ..] => match document.0.get(*head) {
-                    Some(value) => {
-                        let document = from_str(value.get()).map_err(InternalError::SerdeJson)?;
-                        get_docid(&document, tail)
-                    }
-                    None => Ok(Err(DocumentIdExtractionError::MissingDocumentId)),
-                },
-            }
-        }
-
-        /// TODO do not allocate a vec everytime here
-        let primary_key: Vec<_> = self.name().split(PRIMARY_KEY_SPLIT_SYMBOL).collect();
-        get_docid(document, &primary_key)
-    }
-
     /// Returns an `Iterator` that gives all the possible fields names the primary key
     /// can have depending of the first level name and depth of the objects.
     pub fn possible_level_names(&self) -> impl Iterator<Item = (&'a str, &'a str)> + '_ {